Fig 5Pedals, trapwork and una cordaClick a pedal · 1 una corda · 2 sostenuto · 3 sustainall pedals up
A pressed pedal, and what it movesTrap rods, trap levers and lift rodsPedal box, lyre and keybedA pedal is a lever. The foot pushes its front 14 mm down; behind the fulcrum the back end rises 6.2 mm and lifts a maple trap rod up through the lyre to a second lever hung under the keybed. From there each pedal does a different job. The right pedal (sustain) raises the damper tray 7.1 mm, enough to lift every damper off its strings (Fig 4). The middle pedal (sostenuto) turns the sostenuto rod 50°, swinging its lip under the dampers that are already up. The left pedal (una corda) raises a wedge that pushes the key frame, and with it the whole action, 3.0 mm toward the treble. Each hammer then strikes two of its three strings (one of two in the bass) with a less worn part of its felt, for a softer, veiled tone. Springs bring everything back when the foot lifts.